Generally, any electronic device comprises a chip (or more) of semiconductor material on which an actual electronic component is integrated. The chip is usually encapsulated in a package of insulating material in order to be insulated and protected from the external environment. The package exposes conductive pins, which are coupled with corresponding conductive terminals of the chip. For example, such result is achieved through an injection molding operation of plastic material.
Various types of packages are used in the state of the art, which packages are selected according to the application field of the electronic device.
For example, the scaling process of the electronic devices has led to a wide spread of Surface-Mounting Technology (SMT) electronic devices. Particularly, a type of SMT electronic devices has pins exposed on a (lower) surface for mounting the package of the electronic device on a Printed Circuit Board (PCB)—known in the art as “No-Lead” or “Micro-Lead”.
In addition, the SMT electronic devices may also be provided with a (lower) heat sink that is exposed on the mounting surface for dissipating the heat generated by the electronic component during operation (also referred to by means of the acronym EP—Exposed thermal Pad).
The use of electronic components characterized by a high power consumption (for example, power electronic components and central processing units) has led to the development of electronic devices with a further (upper) heat sink, this time exposed on a free (upper) surface of the package opposite the mounting surface, in such a way to dissipate a greater amount of heat produced by the electronic component (also referred to by means of the acronym DSC—Dual Side Cooling).
A known technique (for the manufacturing of electronic devices with exclusively upwards dissipation) provides for forming the package in such a way that the chip is exposed on the upper surface; an upper heat sink may then be fixed directly on the exposed surface of the chip. However, this requires modifying corresponding injection molds of the plastic material (with a consequent increase of the manufacturing costs); furthermore, in the electronic device thus obtained the chip is not insulated from the external environment. Therefore, the operation of the electronic component may be affected by moisture and foreign bodies (e.g., dirt particles) present in the external environment that, by coming into contact with the exposed surface of the chip, may cause malfunctions of the electronic component.
According to another known technique for the manufacturing of electronic devices with upwards dissipation (comprising the DSC electronic devices), the heat sink is fixed onto the chip prior to the molding operation, so that it is fully embedded in the package at the end thereof; at this point, the package is lapped for exposing the upper heat sink. However, this technique involves a mechanical strain for all the elements of the electronic device (chip, package, pins and mechanical connections between them) during the lapping, which may get to damage the electronic device and, consequently, to impair the proper functioning thereof (with subsequent reduction of the manufacturing yield). Moreover, it requires the addition of the lapping operation for the packages, and therefore of machineries necessary for performing such operation (with consequent increase of the manufacturing costs).